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ceph: show non-default options only
[linux/fpc-iii.git] / kernel / sys.c
bloba03d9cd23ed779b2a38d8bf564bac6860d934f2f
1 /*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/export.h>
8 #include <linux/mm.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/reboot.h>
12 #include <linux/prctl.h>
13 #include <linux/highuid.h>
14 #include <linux/fs.h>
15 #include <linux/kmod.h>
16 #include <linux/perf_event.h>
17 #include <linux/resource.h>
18 #include <linux/kernel.h>
19 #include <linux/workqueue.h>
20 #include <linux/capability.h>
21 #include <linux/device.h>
22 #include <linux/key.h>
23 #include <linux/times.h>
24 #include <linux/posix-timers.h>
25 #include <linux/security.h>
26 #include <linux/dcookies.h>
27 #include <linux/suspend.h>
28 #include <linux/tty.h>
29 #include <linux/signal.h>
30 #include <linux/cn_proc.h>
31 #include <linux/getcpu.h>
32 #include <linux/task_io_accounting_ops.h>
33 #include <linux/seccomp.h>
34 #include <linux/cpu.h>
35 #include <linux/personality.h>
36 #include <linux/ptrace.h>
37 #include <linux/fs_struct.h>
38 #include <linux/file.h>
39 #include <linux/mount.h>
40 #include <linux/gfp.h>
41 #include <linux/syscore_ops.h>
42 #include <linux/version.h>
43 #include <linux/ctype.h>
44
45 #include <linux/compat.h>
46 #include <linux/syscalls.h>
47 #include <linux/kprobes.h>
48 #include <linux/user_namespace.h>
49 #include <linux/binfmts.h>
50
51 #include <linux/sched.h>
52 #include <linux/rcupdate.h>
53 #include <linux/uidgid.h>
54 #include <linux/cred.h>
55
56 #include <linux/kmsg_dump.h>
57 /* Move somewhere else to avoid recompiling? */
58 #include <generated/utsrelease.h>
59
60 #include <asm/uaccess.h>
61 #include <asm/io.h>
62 #include <asm/unistd.h>
63
64 #ifndef SET_UNALIGN_CTL
65 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
66 #endif
67 #ifndef GET_UNALIGN_CTL
68 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
69 #endif
70 #ifndef SET_FPEMU_CTL
71 # define SET_FPEMU_CTL(a, b) (-EINVAL)
72 #endif
73 #ifndef GET_FPEMU_CTL
74 # define GET_FPEMU_CTL(a, b) (-EINVAL)
75 #endif
76 #ifndef SET_FPEXC_CTL
77 # define SET_FPEXC_CTL(a, b) (-EINVAL)
78 #endif
79 #ifndef GET_FPEXC_CTL
80 # define GET_FPEXC_CTL(a, b) (-EINVAL)
81 #endif
82 #ifndef GET_ENDIAN
83 # define GET_ENDIAN(a, b) (-EINVAL)
84 #endif
85 #ifndef SET_ENDIAN
86 # define SET_ENDIAN(a, b) (-EINVAL)
87 #endif
88 #ifndef GET_TSC_CTL
89 # define GET_TSC_CTL(a) (-EINVAL)
90 #endif
91 #ifndef SET_TSC_CTL
92 # define SET_TSC_CTL(a) (-EINVAL)
93 #endif
94 #ifndef MPX_ENABLE_MANAGEMENT
95 # define MPX_ENABLE_MANAGEMENT(a) (-EINVAL)
96 #endif
97 #ifndef MPX_DISABLE_MANAGEMENT
98 # define MPX_DISABLE_MANAGEMENT(a) (-EINVAL)
99 #endif
100 #ifndef GET_FP_MODE
101 # define GET_FP_MODE(a) (-EINVAL)
102 #endif
103 #ifndef SET_FP_MODE
104 # define SET_FP_MODE(a,b) (-EINVAL)
105 #endif
106
107 /*
108 * this is where the system-wide overflow UID and GID are defined, for
109 * architectures that now have 32-bit UID/GID but didn't in the past
110 */
111
112 int overflowuid = DEFAULT_OVERFLOWUID;
113 int overflowgid = DEFAULT_OVERFLOWGID;
114
115 EXPORT_SYMBOL(overflowuid);
116 EXPORT_SYMBOL(overflowgid);
117
118 /*
119 * the same as above, but for filesystems which can only store a 16-bit
120 * UID and GID. as such, this is needed on all architectures
121 */
122
123 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
124 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
125
126 EXPORT_SYMBOL(fs_overflowuid);
127 EXPORT_SYMBOL(fs_overflowgid);
128
129 /*
130 * Returns true if current's euid is same as p's uid or euid,
131 * or has CAP_SYS_NICE to p's user_ns.
132 *
133 * Called with rcu_read_lock, creds are safe
134 */
135 static bool set_one_prio_perm(struct task_struct *p)
136 {
137 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
138
139 if (uid_eq(pcred->uid, cred->euid) ||
140 uid_eq(pcred->euid, cred->euid))
141 return true;
142 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
143 return true;
144 return false;
145 }
146
147 /*
148 * set the priority of a task
149 * - the caller must hold the RCU read lock
150 */
151 static int set_one_prio(struct task_struct *p, int niceval, int error)
152 {
153 int no_nice;
154
155 if (!set_one_prio_perm(p)) {
156 error = -EPERM;
157 goto out;
158 }
159 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
160 error = -EACCES;
161 goto out;
162 }
163 no_nice = security_task_setnice(p, niceval);
164 if (no_nice) {
165 error = no_nice;
166 goto out;
167 }
168 if (error == -ESRCH)
169 error = 0;
170 set_user_nice(p, niceval);
171 out:
172 return error;
173 }
174
175 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
176 {
177 struct task_struct *g, *p;
178 struct user_struct *user;
179 const struct cred *cred = current_cred();
180 int error = -EINVAL;
181 struct pid *pgrp;
182 kuid_t uid;
183
184 if (which > PRIO_USER || which < PRIO_PROCESS)
185 goto out;
186
187 /* normalize: avoid signed division (rounding problems) */
188 error = -ESRCH;
189 if (niceval < MIN_NICE)
190 niceval = MIN_NICE;
191 if (niceval > MAX_NICE)
192 niceval = MAX_NICE;
193
194 rcu_read_lock();
195 read_lock(&tasklist_lock);
196 switch (which) {
197 case PRIO_PROCESS:
198 if (who)
199 p = find_task_by_vpid(who);
200 else
201 p = current;
202 if (p)
203 error = set_one_prio(p, niceval, error);
204 break;
205 case PRIO_PGRP:
206 if (who)
207 pgrp = find_vpid(who);
208 else
209 pgrp = task_pgrp(current);
210 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
211 error = set_one_prio(p, niceval, error);
212 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
213 break;
214 case PRIO_USER:
215 uid = make_kuid(cred->user_ns, who);
216 user = cred->user;
217 if (!who)
218 uid = cred->uid;
219 else if (!uid_eq(uid, cred->uid)) {
220 user = find_user(uid);
221 if (!user)
222 goto out_unlock; /* No processes for this user */
223 }
224 do_each_thread(g, p) {
225 if (uid_eq(task_uid(p), uid))
226 error = set_one_prio(p, niceval, error);
227 } while_each_thread(g, p);
228 if (!uid_eq(uid, cred->uid))
229 free_uid(user); /* For find_user() */
230 break;
231 }
232 out_unlock:
233 read_unlock(&tasklist_lock);
234 rcu_read_unlock();
235 out:
236 return error;
237 }
238
239 /*
240 * Ugh. To avoid negative return values, "getpriority()" will
241 * not return the normal nice-value, but a negated value that
242 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
243 * to stay compatible.
244 */
245 SYSCALL_DEFINE2(getpriority, int, which, int, who)
246 {
247 struct task_struct *g, *p;
248 struct user_struct *user;
249 const struct cred *cred = current_cred();
250 long niceval, retval = -ESRCH;
251 struct pid *pgrp;
252 kuid_t uid;
253
254 if (which > PRIO_USER || which < PRIO_PROCESS)
255 return -EINVAL;
256
257 rcu_read_lock();
258 read_lock(&tasklist_lock);
259 switch (which) {
260 case PRIO_PROCESS:
261 if (who)
262 p = find_task_by_vpid(who);
263 else
264 p = current;
265 if (p) {
266 niceval = nice_to_rlimit(task_nice(p));
267 if (niceval > retval)
268 retval = niceval;
269 }
270 break;
271 case PRIO_PGRP:
272 if (who)
273 pgrp = find_vpid(who);
274 else
275 pgrp = task_pgrp(current);
276 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
277 niceval = nice_to_rlimit(task_nice(p));
278 if (niceval > retval)
279 retval = niceval;
280 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
281 break;
282 case PRIO_USER:
283 uid = make_kuid(cred->user_ns, who);
284 user = cred->user;
285 if (!who)
286 uid = cred->uid;
287 else if (!uid_eq(uid, cred->uid)) {
288 user = find_user(uid);
289 if (!user)
290 goto out_unlock; /* No processes for this user */
291 }
292 do_each_thread(g, p) {
293 if (uid_eq(task_uid(p), uid)) {
294 niceval = nice_to_rlimit(task_nice(p));
295 if (niceval > retval)
296 retval = niceval;
297 }
298 } while_each_thread(g, p);
299 if (!uid_eq(uid, cred->uid))
300 free_uid(user); /* for find_user() */
301 break;
302 }
303 out_unlock:
304 read_unlock(&tasklist_lock);
305 rcu_read_unlock();
306
307 return retval;
308 }
309
310 /*
311 * Unprivileged users may change the real gid to the effective gid
312 * or vice versa. (BSD-style)
313 *
314 * If you set the real gid at all, or set the effective gid to a value not
315 * equal to the real gid, then the saved gid is set to the new effective gid.
316 *
317 * This makes it possible for a setgid program to completely drop its
318 * privileges, which is often a useful assertion to make when you are doing
319 * a security audit over a program.
320 *
321 * The general idea is that a program which uses just setregid() will be
322 * 100% compatible with BSD. A program which uses just setgid() will be
323 * 100% compatible with POSIX with saved IDs.
324 *
325 * SMP: There are not races, the GIDs are checked only by filesystem
326 * operations (as far as semantic preservation is concerned).
327 */
328 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
329 {
330 struct user_namespace *ns = current_user_ns();
331 const struct cred *old;
332 struct cred *new;
333 int retval;
334 kgid_t krgid, kegid;
335
336 krgid = make_kgid(ns, rgid);
337 kegid = make_kgid(ns, egid);
338
339 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
340 return -EINVAL;
341 if ((egid != (gid_t) -1) && !gid_valid(kegid))
342 return -EINVAL;
343
344 new = prepare_creds();
345 if (!new)
346 return -ENOMEM;
347 old = current_cred();
348
349 retval = -EPERM;
350 if (rgid != (gid_t) -1) {
351 if (gid_eq(old->gid, krgid) ||
352 gid_eq(old->egid, krgid) ||
353 ns_capable(old->user_ns, CAP_SETGID))
354 new->gid = krgid;
355 else
356 goto error;
357 }
358 if (egid != (gid_t) -1) {
359 if (gid_eq(old->gid, kegid) ||
360 gid_eq(old->egid, kegid) ||
361 gid_eq(old->sgid, kegid) ||
362 ns_capable(old->user_ns, CAP_SETGID))
363 new->egid = kegid;
364 else
365 goto error;
366 }
367
368 if (rgid != (gid_t) -1 ||
369 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
370 new->sgid = new->egid;
371 new->fsgid = new->egid;
372
373 return commit_creds(new);
374
375 error:
376 abort_creds(new);
377 return retval;
378 }
379
380 /*
381 * setgid() is implemented like SysV w/ SAVED_IDS
382 *
383 * SMP: Same implicit races as above.
384 */
385 SYSCALL_DEFINE1(setgid, gid_t, gid)
386 {
387 struct user_namespace *ns = current_user_ns();
388 const struct cred *old;
389 struct cred *new;
390 int retval;
391 kgid_t kgid;
392
393 kgid = make_kgid(ns, gid);
394 if (!gid_valid(kgid))
395 return -EINVAL;
396
397 new = prepare_creds();
398 if (!new)
399 return -ENOMEM;
400 old = current_cred();
401
402 retval = -EPERM;
403 if (ns_capable(old->user_ns, CAP_SETGID))
404 new->gid = new->egid = new->sgid = new->fsgid = kgid;
405 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
406 new->egid = new->fsgid = kgid;
407 else
408 goto error;
409
410 return commit_creds(new);
411
412 error:
413 abort_creds(new);
414 return retval;
415 }
416
417 /*
418 * change the user struct in a credentials set to match the new UID
419 */
420 static int set_user(struct cred *new)
421 {
422 struct user_struct *new_user;
423
424 new_user = alloc_uid(new->uid);
425 if (!new_user)
426 return -EAGAIN;
427
428 /*
429 * We don't fail in case of NPROC limit excess here because too many
430 * poorly written programs don't check set*uid() return code, assuming
431 * it never fails if called by root. We may still enforce NPROC limit
432 * for programs doing set*uid()+execve() by harmlessly deferring the
433 * failure to the execve() stage.
434 */
435 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
436 new_user != INIT_USER)
437 current->flags |= PF_NPROC_EXCEEDED;
438 else
439 current->flags &= ~PF_NPROC_EXCEEDED;
440
441 free_uid(new->user);
442 new->user = new_user;
443 return 0;
444 }
445
446 /*
447 * Unprivileged users may change the real uid to the effective uid
448 * or vice versa. (BSD-style)
449 *
450 * If you set the real uid at all, or set the effective uid to a value not
451 * equal to the real uid, then the saved uid is set to the new effective uid.
452 *
453 * This makes it possible for a setuid program to completely drop its
454 * privileges, which is often a useful assertion to make when you are doing
455 * a security audit over a program.
456 *
457 * The general idea is that a program which uses just setreuid() will be
458 * 100% compatible with BSD. A program which uses just setuid() will be
459 * 100% compatible with POSIX with saved IDs.
460 */
461 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
462 {
463 struct user_namespace *ns = current_user_ns();
464 const struct cred *old;
465 struct cred *new;
466 int retval;
467 kuid_t kruid, keuid;
468
469 kruid = make_kuid(ns, ruid);
470 keuid = make_kuid(ns, euid);
471
472 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
473 return -EINVAL;
474 if ((euid != (uid_t) -1) && !uid_valid(keuid))
475 return -EINVAL;
476
477 new = prepare_creds();
478 if (!new)
479 return -ENOMEM;
480 old = current_cred();
481
482 retval = -EPERM;
483 if (ruid != (uid_t) -1) {
484 new->uid = kruid;
485 if (!uid_eq(old->uid, kruid) &&
486 !uid_eq(old->euid, kruid) &&
487 !ns_capable(old->user_ns, CAP_SETUID))
488 goto error;
489 }
490
491 if (euid != (uid_t) -1) {
492 new->euid = keuid;
493 if (!uid_eq(old->uid, keuid) &&
494 !uid_eq(old->euid, keuid) &&
495 !uid_eq(old->suid, keuid) &&
496 !ns_capable(old->user_ns, CAP_SETUID))
497 goto error;
498 }
499
500 if (!uid_eq(new->uid, old->uid)) {
501 retval = set_user(new);
502 if (retval < 0)
503 goto error;
504 }
505 if (ruid != (uid_t) -1 ||
506 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
507 new->suid = new->euid;
508 new->fsuid = new->euid;
509
510 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
511 if (retval < 0)
512 goto error;
513
514 return commit_creds(new);
515
516 error:
517 abort_creds(new);
518 return retval;
519 }
520
521 /*
522 * setuid() is implemented like SysV with SAVED_IDS
523 *
524 * Note that SAVED_ID's is deficient in that a setuid root program
525 * like sendmail, for example, cannot set its uid to be a normal
526 * user and then switch back, because if you're root, setuid() sets
527 * the saved uid too. If you don't like this, blame the bright people
528 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
529 * will allow a root program to temporarily drop privileges and be able to
530 * regain them by swapping the real and effective uid.
531 */
532 SYSCALL_DEFINE1(setuid, uid_t, uid)
533 {
534 struct user_namespace *ns = current_user_ns();
535 const struct cred *old;
536 struct cred *new;
537 int retval;
538 kuid_t kuid;
539
540 kuid = make_kuid(ns, uid);
541 if (!uid_valid(kuid))
542 return -EINVAL;
543
544 new = prepare_creds();
545 if (!new)
546 return -ENOMEM;
547 old = current_cred();
548
549 retval = -EPERM;
550 if (ns_capable(old->user_ns, CAP_SETUID)) {
551 new->suid = new->uid = kuid;
552 if (!uid_eq(kuid, old->uid)) {
553 retval = set_user(new);
554 if (retval < 0)
555 goto error;
556 }
557 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
558 goto error;
559 }
560
561 new->fsuid = new->euid = kuid;
562
563 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
564 if (retval < 0)
565 goto error;
566
567 return commit_creds(new);
568
569 error:
570 abort_creds(new);
571 return retval;
572 }
573
574
575 /*
576 * This function implements a generic ability to update ruid, euid,
577 * and suid. This allows you to implement the 4.4 compatible seteuid().
578 */
579 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
580 {
581 struct user_namespace *ns = current_user_ns();
582 const struct cred *old;
583 struct cred *new;
584 int retval;
585 kuid_t kruid, keuid, ksuid;
586
587 kruid = make_kuid(ns, ruid);
588 keuid = make_kuid(ns, euid);
589 ksuid = make_kuid(ns, suid);
590
591 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
592 return -EINVAL;
593
594 if ((euid != (uid_t) -1) && !uid_valid(keuid))
595 return -EINVAL;
596
597 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
598 return -EINVAL;
599
600 new = prepare_creds();
601 if (!new)
602 return -ENOMEM;
603
604 old = current_cred();
605
606 retval = -EPERM;
607 if (!ns_capable(old->user_ns, CAP_SETUID)) {
608 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
609 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
610 goto error;
611 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
612 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
613 goto error;
614 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
615 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
616 goto error;
617 }
618
619 if (ruid != (uid_t) -1) {
620 new->uid = kruid;
621 if (!uid_eq(kruid, old->uid)) {
622 retval = set_user(new);
623 if (retval < 0)
624 goto error;
625 }
626 }
627 if (euid != (uid_t) -1)
628 new->euid = keuid;
629 if (suid != (uid_t) -1)
630 new->suid = ksuid;
631 new->fsuid = new->euid;
632
633 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
634 if (retval < 0)
635 goto error;
636
637 return commit_creds(new);
638
639 error:
640 abort_creds(new);
641 return retval;
642 }
643
644 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
645 {
646 const struct cred *cred = current_cred();
647 int retval;
648 uid_t ruid, euid, suid;
649
650 ruid = from_kuid_munged(cred->user_ns, cred->uid);
651 euid = from_kuid_munged(cred->user_ns, cred->euid);
652 suid = from_kuid_munged(cred->user_ns, cred->suid);
653
654 retval = put_user(ruid, ruidp);
655 if (!retval) {
656 retval = put_user(euid, euidp);
657 if (!retval)
658 return put_user(suid, suidp);
659 }
660 return retval;
661 }
662
663 /*
664 * Same as above, but for rgid, egid, sgid.
665 */
666 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
667 {
668 struct user_namespace *ns = current_user_ns();
669 const struct cred *old;
670 struct cred *new;
671 int retval;
672 kgid_t krgid, kegid, ksgid;
673
674 krgid = make_kgid(ns, rgid);
675 kegid = make_kgid(ns, egid);
676 ksgid = make_kgid(ns, sgid);
677
678 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
679 return -EINVAL;
680 if ((egid != (gid_t) -1) && !gid_valid(kegid))
681 return -EINVAL;
682 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
683 return -EINVAL;
684
685 new = prepare_creds();
686 if (!new)
687 return -ENOMEM;
688 old = current_cred();
689
690 retval = -EPERM;
691 if (!ns_capable(old->user_ns, CAP_SETGID)) {
692 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
693 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
694 goto error;
695 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
696 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
697 goto error;
698 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
699 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
700 goto error;
701 }
702
703 if (rgid != (gid_t) -1)
704 new->gid = krgid;
705 if (egid != (gid_t) -1)
706 new->egid = kegid;
707 if (sgid != (gid_t) -1)
708 new->sgid = ksgid;
709 new->fsgid = new->egid;
710
711 return commit_creds(new);
712
713 error:
714 abort_creds(new);
715 return retval;
716 }
717
718 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
719 {
720 const struct cred *cred = current_cred();
721 int retval;
722 gid_t rgid, egid, sgid;
723
724 rgid = from_kgid_munged(cred->user_ns, cred->gid);
725 egid = from_kgid_munged(cred->user_ns, cred->egid);
726 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
727
728 retval = put_user(rgid, rgidp);
729 if (!retval) {
730 retval = put_user(egid, egidp);
731 if (!retval)
732 retval = put_user(sgid, sgidp);
733 }
734
735 return retval;
736 }
737
738
739 /*
740 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
741 * is used for "access()" and for the NFS daemon (letting nfsd stay at
742 * whatever uid it wants to). It normally shadows "euid", except when
743 * explicitly set by setfsuid() or for access..
744 */
745 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
746 {
747 const struct cred *old;
748 struct cred *new;
749 uid_t old_fsuid;
750 kuid_t kuid;
751
752 old = current_cred();
753 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
754
755 kuid = make_kuid(old->user_ns, uid);
756 if (!uid_valid(kuid))
757 return old_fsuid;
758
759 new = prepare_creds();
760 if (!new)
761 return old_fsuid;
762
763 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
764 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
765 ns_capable(old->user_ns, CAP_SETUID)) {
766 if (!uid_eq(kuid, old->fsuid)) {
767 new->fsuid = kuid;
768 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
769 goto change_okay;
770 }
771 }
772
773 abort_creds(new);
774 return old_fsuid;
775
776 change_okay:
777 commit_creds(new);
778 return old_fsuid;
779 }
780
781 /*
782 * Samma på svenska..
783 */
784 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
785 {
786 const struct cred *old;
787 struct cred *new;
788 gid_t old_fsgid;
789 kgid_t kgid;
790
791 old = current_cred();
792 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
793
794 kgid = make_kgid(old->user_ns, gid);
795 if (!gid_valid(kgid))
796 return old_fsgid;
797
798 new = prepare_creds();
799 if (!new)
800 return old_fsgid;
801
802 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
803 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
804 ns_capable(old->user_ns, CAP_SETGID)) {
805 if (!gid_eq(kgid, old->fsgid)) {
806 new->fsgid = kgid;
807 goto change_okay;
808 }
809 }
810
811 abort_creds(new);
812 return old_fsgid;
813
814 change_okay:
815 commit_creds(new);
816 return old_fsgid;
817 }
818
819 /**
820 * sys_getpid - return the thread group id of the current process
821 *
822 * Note, despite the name, this returns the tgid not the pid. The tgid and
823 * the pid are identical unless CLONE_THREAD was specified on clone() in
824 * which case the tgid is the same in all threads of the same group.
825 *
826 * This is SMP safe as current->tgid does not change.
827 */
828 SYSCALL_DEFINE0(getpid)
829 {
830 return task_tgid_vnr(current);
831 }
832
833 /* Thread ID - the internal kernel "pid" */
834 SYSCALL_DEFINE0(gettid)
835 {
836 return task_pid_vnr(current);
837 }
838
839 /*
840 * Accessing ->real_parent is not SMP-safe, it could
841 * change from under us. However, we can use a stale
842 * value of ->real_parent under rcu_read_lock(), see
843 * release_task()->call_rcu(delayed_put_task_struct).
844 */
845 SYSCALL_DEFINE0(getppid)
846 {
847 int pid;
848
849 rcu_read_lock();
850 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
851 rcu_read_unlock();
852
853 return pid;
854 }
855
856 SYSCALL_DEFINE0(getuid)
857 {
858 /* Only we change this so SMP safe */
859 return from_kuid_munged(current_user_ns(), current_uid());
860 }
861
862 SYSCALL_DEFINE0(geteuid)
863 {
864 /* Only we change this so SMP safe */
865 return from_kuid_munged(current_user_ns(), current_euid());
866 }
867
868 SYSCALL_DEFINE0(getgid)
869 {
870 /* Only we change this so SMP safe */
871 return from_kgid_munged(current_user_ns(), current_gid());
872 }
873
874 SYSCALL_DEFINE0(getegid)
875 {
876 /* Only we change this so SMP safe */
877 return from_kgid_munged(current_user_ns(), current_egid());
878 }
879
880 void do_sys_times(struct tms *tms)
881 {
882 cputime_t tgutime, tgstime, cutime, cstime;
883
884 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
885 cutime = current->signal->cutime;
886 cstime = current->signal->cstime;
887 tms->tms_utime = cputime_to_clock_t(tgutime);
888 tms->tms_stime = cputime_to_clock_t(tgstime);
889 tms->tms_cutime = cputime_to_clock_t(cutime);
890 tms->tms_cstime = cputime_to_clock_t(cstime);
891 }
892
893 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
894 {
895 if (tbuf) {
896 struct tms tmp;
897
898 do_sys_times(&tmp);
899 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
900 return -EFAULT;
901 }
902 force_successful_syscall_return();
903 return (long) jiffies_64_to_clock_t(get_jiffies_64());
904 }
905
906 /*
907 * This needs some heavy checking ...
908 * I just haven't the stomach for it. I also don't fully
909 * understand sessions/pgrp etc. Let somebody who does explain it.
910 *
911 * OK, I think I have the protection semantics right.... this is really
912 * only important on a multi-user system anyway, to make sure one user
913 * can't send a signal to a process owned by another. -TYT, 12/12/91
914 *
915 * !PF_FORKNOEXEC check to conform completely to POSIX.
916 */
917 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
918 {
919 struct task_struct *p;
920 struct task_struct *group_leader = current->group_leader;
921 struct pid *pgrp;
922 int err;
923
924 if (!pid)
925 pid = task_pid_vnr(group_leader);
926 if (!pgid)
927 pgid = pid;
928 if (pgid < 0)
929 return -EINVAL;
930 rcu_read_lock();
931
932 /* From this point forward we keep holding onto the tasklist lock
933 * so that our parent does not change from under us. -DaveM
934 */
935 write_lock_irq(&tasklist_lock);
936
937 err = -ESRCH;
938 p = find_task_by_vpid(pid);
939 if (!p)
940 goto out;
941
942 err = -EINVAL;
943 if (!thread_group_leader(p))
944 goto out;
945
946 if (same_thread_group(p->real_parent, group_leader)) {
947 err = -EPERM;
948 if (task_session(p) != task_session(group_leader))
949 goto out;
950 err = -EACCES;
951 if (!(p->flags & PF_FORKNOEXEC))
952 goto out;
953 } else {
954 err = -ESRCH;
955 if (p != group_leader)
956 goto out;
957 }
958
959 err = -EPERM;
960 if (p->signal->leader)
961 goto out;
962
963 pgrp = task_pid(p);
964 if (pgid != pid) {
965 struct task_struct *g;
966
967 pgrp = find_vpid(pgid);
968 g = pid_task(pgrp, PIDTYPE_PGID);
969 if (!g || task_session(g) != task_session(group_leader))
970 goto out;
971 }
972
973 err = security_task_setpgid(p, pgid);
974 if (err)
975 goto out;
976
977 if (task_pgrp(p) != pgrp)
978 change_pid(p, PIDTYPE_PGID, pgrp);
979
980 err = 0;
981 out:
982 /* All paths lead to here, thus we are safe. -DaveM */
983 write_unlock_irq(&tasklist_lock);
984 rcu_read_unlock();
985 return err;
986 }
987
988 SYSCALL_DEFINE1(getpgid, pid_t, pid)
989 {
990 struct task_struct *p;
991 struct pid *grp;
992 int retval;
993
994 rcu_read_lock();
995 if (!pid)
996 grp = task_pgrp(current);
997 else {
998 retval = -ESRCH;
999 p = find_task_by_vpid(pid);
1000 if (!p)
1001 goto out;
1002 grp = task_pgrp(p);
1003 if (!grp)
1004 goto out;
1005
1006 retval = security_task_getpgid(p);
1007 if (retval)
1008 goto out;
1009 }
1010 retval = pid_vnr(grp);
1011 out:
1012 rcu_read_unlock();
1013 return retval;
1014 }
1015
1016 #ifdef __ARCH_WANT_SYS_GETPGRP
1017
1018 SYSCALL_DEFINE0(getpgrp)
1019 {
1020 return sys_getpgid(0);
1021 }
1022
1023 #endif
1024
1025 SYSCALL_DEFINE1(getsid, pid_t, pid)
1026 {
1027 struct task_struct *p;
1028 struct pid *sid;
1029 int retval;
1030
1031 rcu_read_lock();
1032 if (!pid)
1033 sid = task_session(current);
1034 else {
1035 retval = -ESRCH;
1036 p = find_task_by_vpid(pid);
1037 if (!p)
1038 goto out;
1039 sid = task_session(p);
1040 if (!sid)
1041 goto out;
1042
1043 retval = security_task_getsid(p);
1044 if (retval)
1045 goto out;
1046 }
1047 retval = pid_vnr(sid);
1048 out:
1049 rcu_read_unlock();
1050 return retval;
1051 }
1052
1053 static void set_special_pids(struct pid *pid)
1054 {
1055 struct task_struct *curr = current->group_leader;
1056
1057 if (task_session(curr) != pid)
1058 change_pid(curr, PIDTYPE_SID, pid);
1059
1060 if (task_pgrp(curr) != pid)
1061 change_pid(curr, PIDTYPE_PGID, pid);
1062 }
1063
1064 SYSCALL_DEFINE0(setsid)
1065 {
1066 struct task_struct *group_leader = current->group_leader;
1067 struct pid *sid = task_pid(group_leader);
1068 pid_t session = pid_vnr(sid);
1069 int err = -EPERM;
1070
1071 write_lock_irq(&tasklist_lock);
1072 /* Fail if I am already a session leader */
1073 if (group_leader->signal->leader)
1074 goto out;
1075
1076 /* Fail if a process group id already exists that equals the
1077 * proposed session id.
1078 */
1079 if (pid_task(sid, PIDTYPE_PGID))
1080 goto out;
1081
1082 group_leader->signal->leader = 1;
1083 set_special_pids(sid);
1084
1085 proc_clear_tty(group_leader);
1086
1087 err = session;
1088 out:
1089 write_unlock_irq(&tasklist_lock);
1090 if (err > 0) {
1091 proc_sid_connector(group_leader);
1092 sched_autogroup_create_attach(group_leader);
1093 }
1094 return err;
1095 }
1096
1097 DECLARE_RWSEM(uts_sem);
1098
1099 #ifdef COMPAT_UTS_MACHINE
1100 #define override_architecture(name) \
1101 (personality(current->personality) == PER_LINUX32 && \
1102 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1103 sizeof(COMPAT_UTS_MACHINE)))
1104 #else
1105 #define override_architecture(name) 0
1106 #endif
1107
1108 /*
1109 * Work around broken programs that cannot handle "Linux 3.0".
1110 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1111 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60.
1112 */
1113 static int override_release(char __user *release, size_t len)
1114 {
1115 int ret = 0;
1116
1117 if (current->personality & UNAME26) {
1118 const char *rest = UTS_RELEASE;
1119 char buf[65] = { 0 };
1120 int ndots = 0;
1121 unsigned v;
1122 size_t copy;
1123
1124 while (*rest) {
1125 if (*rest == '.' && ++ndots >= 3)
1126 break;
1127 if (!isdigit(*rest) && *rest != '.')
1128 break;
1129 rest++;
1130 }
1131 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1132 copy = clamp_t(size_t, len, 1, sizeof(buf));
1133 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1134 ret = copy_to_user(release, buf, copy + 1);
1135 }
1136 return ret;
1137 }
1138
1139 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1140 {
1141 int errno = 0;
1142
1143 down_read(&uts_sem);
1144 if (copy_to_user(name, utsname(), sizeof *name))
1145 errno = -EFAULT;
1146 up_read(&uts_sem);
1147
1148 if (!errno && override_release(name->release, sizeof(name->release)))
1149 errno = -EFAULT;
1150 if (!errno && override_architecture(name))
1151 errno = -EFAULT;
1152 return errno;
1153 }
1154
1155 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1156 /*
1157 * Old cruft
1158 */
1159 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1160 {
1161 int error = 0;
1162
1163 if (!name)
1164 return -EFAULT;
1165
1166 down_read(&uts_sem);
1167 if (copy_to_user(name, utsname(), sizeof(*name)))
1168 error = -EFAULT;
1169 up_read(&uts_sem);
1170
1171 if (!error && override_release(name->release, sizeof(name->release)))
1172 error = -EFAULT;
1173 if (!error && override_architecture(name))
1174 error = -EFAULT;
1175 return error;
1176 }
1177
1178 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1179 {
1180 int error;
1181
1182 if (!name)
1183 return -EFAULT;
1184 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1185 return -EFAULT;
1186
1187 down_read(&uts_sem);
1188 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1189 __OLD_UTS_LEN);
1190 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1191 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1192 __OLD_UTS_LEN);
1193 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1194 error |= __copy_to_user(&name->release, &utsname()->release,
1195 __OLD_UTS_LEN);
1196 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1197 error |= __copy_to_user(&name->version, &utsname()->version,
1198 __OLD_UTS_LEN);
1199 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1200 error |= __copy_to_user(&name->machine, &utsname()->machine,
1201 __OLD_UTS_LEN);
1202 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1203 up_read(&uts_sem);
1204
1205 if (!error && override_architecture(name))
1206 error = -EFAULT;
1207 if (!error && override_release(name->release, sizeof(name->release)))
1208 error = -EFAULT;
1209 return error ? -EFAULT : 0;
1210 }
1211 #endif
1212
1213 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1214 {
1215 int errno;
1216 char tmp[__NEW_UTS_LEN];
1217
1218 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1219 return -EPERM;
1220
1221 if (len < 0 || len > __NEW_UTS_LEN)
1222 return -EINVAL;
1223 down_write(&uts_sem);
1224 errno = -EFAULT;
1225 if (!copy_from_user(tmp, name, len)) {
1226 struct new_utsname *u = utsname();
1227
1228 memcpy(u->nodename, tmp, len);
1229 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1230 errno = 0;
1231 uts_proc_notify(UTS_PROC_HOSTNAME);
1232 }
1233 up_write(&uts_sem);
1234 return errno;
1235 }
1236
1237 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1238
1239 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1240 {
1241 int i, errno;
1242 struct new_utsname *u;
1243
1244 if (len < 0)
1245 return -EINVAL;
1246 down_read(&uts_sem);
1247 u = utsname();
1248 i = 1 + strlen(u->nodename);
1249 if (i > len)
1250 i = len;
1251 errno = 0;
1252 if (copy_to_user(name, u->nodename, i))
1253 errno = -EFAULT;
1254 up_read(&uts_sem);
1255 return errno;
1256 }
1257
1258 #endif
1259
1260 /*
1261 * Only setdomainname; getdomainname can be implemented by calling
1262 * uname()
1263 */
1264 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1265 {
1266 int errno;
1267 char tmp[__NEW_UTS_LEN];
1268
1269 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1270 return -EPERM;
1271 if (len < 0 || len > __NEW_UTS_LEN)
1272 return -EINVAL;
1273
1274 down_write(&uts_sem);
1275 errno = -EFAULT;
1276 if (!copy_from_user(tmp, name, len)) {
1277 struct new_utsname *u = utsname();
1278
1279 memcpy(u->domainname, tmp, len);
1280 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1281 errno = 0;
1282 uts_proc_notify(UTS_PROC_DOMAINNAME);
1283 }
1284 up_write(&uts_sem);
1285 return errno;
1286 }
1287
1288 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1289 {
1290 struct rlimit value;
1291 int ret;
1292
1293 ret = do_prlimit(current, resource, NULL, &value);
1294 if (!ret)
1295 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1296
1297 return ret;
1298 }
1299
1300 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1301
1302 /*
1303 * Back compatibility for getrlimit. Needed for some apps.
1304 */
1305 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1306 struct rlimit __user *, rlim)
1307 {
1308 struct rlimit x;
1309 if (resource >= RLIM_NLIMITS)
1310 return -EINVAL;
1311
1312 task_lock(current->group_leader);
1313 x = current->signal->rlim[resource];
1314 task_unlock(current->group_leader);
1315 if (x.rlim_cur > 0x7FFFFFFF)
1316 x.rlim_cur = 0x7FFFFFFF;
1317 if (x.rlim_max > 0x7FFFFFFF)
1318 x.rlim_max = 0x7FFFFFFF;
1319 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1320 }
1321
1322 #endif
1323
1324 static inline bool rlim64_is_infinity(__u64 rlim64)
1325 {
1326 #if BITS_PER_LONG < 64
1327 return rlim64 >= ULONG_MAX;
1328 #else
1329 return rlim64 == RLIM64_INFINITY;
1330 #endif
1331 }
1332
1333 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1334 {
1335 if (rlim->rlim_cur == RLIM_INFINITY)
1336 rlim64->rlim_cur = RLIM64_INFINITY;
1337 else
1338 rlim64->rlim_cur = rlim->rlim_cur;
1339 if (rlim->rlim_max == RLIM_INFINITY)
1340 rlim64->rlim_max = RLIM64_INFINITY;
1341 else
1342 rlim64->rlim_max = rlim->rlim_max;
1343 }
1344
1345 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1346 {
1347 if (rlim64_is_infinity(rlim64->rlim_cur))
1348 rlim->rlim_cur = RLIM_INFINITY;
1349 else
1350 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1351 if (rlim64_is_infinity(rlim64->rlim_max))
1352 rlim->rlim_max = RLIM_INFINITY;
1353 else
1354 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1355 }
1356
1357 /* make sure you are allowed to change @tsk limits before calling this */
1358 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1359 struct rlimit *new_rlim, struct rlimit *old_rlim)
1360 {
1361 struct rlimit *rlim;
1362 int retval = 0;
1363
1364 if (resource >= RLIM_NLIMITS)
1365 return -EINVAL;
1366 if (new_rlim) {
1367 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1368 return -EINVAL;
1369 if (resource == RLIMIT_NOFILE &&
1370 new_rlim->rlim_max > sysctl_nr_open)
1371 return -EPERM;
1372 }
1373
1374 /* protect tsk->signal and tsk->sighand from disappearing */
1375 read_lock(&tasklist_lock);
1376 if (!tsk->sighand) {
1377 retval = -ESRCH;
1378 goto out;
1379 }
1380
1381 rlim = tsk->signal->rlim + resource;
1382 task_lock(tsk->group_leader);
1383 if (new_rlim) {
1384 /* Keep the capable check against init_user_ns until
1385 cgroups can contain all limits */
1386 if (new_rlim->rlim_max > rlim->rlim_max &&
1387 !capable(CAP_SYS_RESOURCE))
1388 retval = -EPERM;
1389 if (!retval)
1390 retval = security_task_setrlimit(tsk->group_leader,
1391 resource, new_rlim);
1392 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1393 /*
1394 * The caller is asking for an immediate RLIMIT_CPU
1395 * expiry. But we use the zero value to mean "it was
1396 * never set". So let's cheat and make it one second
1397 * instead
1398 */
1399 new_rlim->rlim_cur = 1;
1400 }
1401 }
1402 if (!retval) {
1403 if (old_rlim)
1404 *old_rlim = *rlim;
1405 if (new_rlim)
1406 *rlim = *new_rlim;
1407 }
1408 task_unlock(tsk->group_leader);
1409
1410 /*
1411 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1412 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1413 * very long-standing error, and fixing it now risks breakage of
1414 * applications, so we live with it
1415 */
1416 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1417 new_rlim->rlim_cur != RLIM_INFINITY)
1418 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1419 out:
1420 read_unlock(&tasklist_lock);
1421 return retval;
1422 }
1423
1424 /* rcu lock must be held */
1425 static int check_prlimit_permission(struct task_struct *task)
1426 {
1427 const struct cred *cred = current_cred(), *tcred;
1428
1429 if (current == task)
1430 return 0;
1431
1432 tcred = __task_cred(task);
1433 if (uid_eq(cred->uid, tcred->euid) &&
1434 uid_eq(cred->uid, tcred->suid) &&
1435 uid_eq(cred->uid, tcred->uid) &&
1436 gid_eq(cred->gid, tcred->egid) &&
1437 gid_eq(cred->gid, tcred->sgid) &&
1438 gid_eq(cred->gid, tcred->gid))
1439 return 0;
1440 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1441 return 0;
1442
1443 return -EPERM;
1444 }
1445
1446 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1447 const struct rlimit64 __user *, new_rlim,
1448 struct rlimit64 __user *, old_rlim)
1449 {
1450 struct rlimit64 old64, new64;
1451 struct rlimit old, new;
1452 struct task_struct *tsk;
1453 int ret;
1454
1455 if (new_rlim) {
1456 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1457 return -EFAULT;
1458 rlim64_to_rlim(&new64, &new);
1459 }
1460
1461 rcu_read_lock();
1462 tsk = pid ? find_task_by_vpid(pid) : current;
1463 if (!tsk) {
1464 rcu_read_unlock();
1465 return -ESRCH;
1466 }
1467 ret = check_prlimit_permission(tsk);
1468 if (ret) {
1469 rcu_read_unlock();
1470 return ret;
1471 }
1472 get_task_struct(tsk);
1473 rcu_read_unlock();
1474
1475 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1476 old_rlim ? &old : NULL);
1477
1478 if (!ret && old_rlim) {
1479 rlim_to_rlim64(&old, &old64);
1480 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1481 ret = -EFAULT;
1482 }
1483
1484 put_task_struct(tsk);
1485 return ret;
1486 }
1487
1488 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1489 {
1490 struct rlimit new_rlim;
1491
1492 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1493 return -EFAULT;
1494 return do_prlimit(current, resource, &new_rlim, NULL);
1495 }
1496
1497 /*
1498 * It would make sense to put struct rusage in the task_struct,
1499 * except that would make the task_struct be *really big*. After
1500 * task_struct gets moved into malloc'ed memory, it would
1501 * make sense to do this. It will make moving the rest of the information
1502 * a lot simpler! (Which we're not doing right now because we're not
1503 * measuring them yet).
1504 *
1505 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1506 * races with threads incrementing their own counters. But since word
1507 * reads are atomic, we either get new values or old values and we don't
1508 * care which for the sums. We always take the siglock to protect reading
1509 * the c* fields from p->signal from races with exit.c updating those
1510 * fields when reaping, so a sample either gets all the additions of a
1511 * given child after it's reaped, or none so this sample is before reaping.
1512 *
1513 * Locking:
1514 * We need to take the siglock for CHILDEREN, SELF and BOTH
1515 * for the cases current multithreaded, non-current single threaded
1516 * non-current multithreaded. Thread traversal is now safe with
1517 * the siglock held.
1518 * Strictly speaking, we donot need to take the siglock if we are current and
1519 * single threaded, as no one else can take our signal_struct away, no one
1520 * else can reap the children to update signal->c* counters, and no one else
1521 * can race with the signal-> fields. If we do not take any lock, the
1522 * signal-> fields could be read out of order while another thread was just
1523 * exiting. So we should place a read memory barrier when we avoid the lock.
1524 * On the writer side, write memory barrier is implied in __exit_signal
1525 * as __exit_signal releases the siglock spinlock after updating the signal->
1526 * fields. But we don't do this yet to keep things simple.
1527 *
1528 */
1529
1530 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1531 {
1532 r->ru_nvcsw += t->nvcsw;
1533 r->ru_nivcsw += t->nivcsw;
1534 r->ru_minflt += t->min_flt;
1535 r->ru_majflt += t->maj_flt;
1536 r->ru_inblock += task_io_get_inblock(t);
1537 r->ru_oublock += task_io_get_oublock(t);
1538 }
1539
1540 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1541 {
1542 struct task_struct *t;
1543 unsigned long flags;
1544 cputime_t tgutime, tgstime, utime, stime;
1545 unsigned long maxrss = 0;
1546
1547 memset((char *)r, 0, sizeof (*r));
1548 utime = stime = 0;
1549
1550 if (who == RUSAGE_THREAD) {
1551 task_cputime_adjusted(current, &utime, &stime);
1552 accumulate_thread_rusage(p, r);
1553 maxrss = p->signal->maxrss;
1554 goto out;
1555 }
1556
1557 if (!lock_task_sighand(p, &flags))
1558 return;
1559
1560 switch (who) {
1561 case RUSAGE_BOTH:
1562 case RUSAGE_CHILDREN:
1563 utime = p->signal->cutime;
1564 stime = p->signal->cstime;
1565 r->ru_nvcsw = p->signal->cnvcsw;
1566 r->ru_nivcsw = p->signal->cnivcsw;
1567 r->ru_minflt = p->signal->cmin_flt;
1568 r->ru_majflt = p->signal->cmaj_flt;
1569 r->ru_inblock = p->signal->cinblock;
1570 r->ru_oublock = p->signal->coublock;
1571 maxrss = p->signal->cmaxrss;
1572
1573 if (who == RUSAGE_CHILDREN)
1574 break;
1575
1576 case RUSAGE_SELF:
1577 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1578 utime += tgutime;
1579 stime += tgstime;
1580 r->ru_nvcsw += p->signal->nvcsw;
1581 r->ru_nivcsw += p->signal->nivcsw;
1582 r->ru_minflt += p->signal->min_flt;
1583 r->ru_majflt += p->signal->maj_flt;
1584 r->ru_inblock += p->signal->inblock;
1585 r->ru_oublock += p->signal->oublock;
1586 if (maxrss < p->signal->maxrss)
1587 maxrss = p->signal->maxrss;
1588 t = p;
1589 do {
1590 accumulate_thread_rusage(t, r);
1591 } while_each_thread(p, t);
1592 break;
1593
1594 default:
1595 BUG();
1596 }
1597 unlock_task_sighand(p, &flags);
1598
1599 out:
1600 cputime_to_timeval(utime, &r->ru_utime);
1601 cputime_to_timeval(stime, &r->ru_stime);
1602
1603 if (who != RUSAGE_CHILDREN) {
1604 struct mm_struct *mm = get_task_mm(p);
1605
1606 if (mm) {
1607 setmax_mm_hiwater_rss(&maxrss, mm);
1608 mmput(mm);
1609 }
1610 }
1611 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1612 }
1613
1614 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1615 {
1616 struct rusage r;
1617
1618 k_getrusage(p, who, &r);
1619 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1620 }
1621
1622 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1623 {
1624 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1625 who != RUSAGE_THREAD)
1626 return -EINVAL;
1627 return getrusage(current, who, ru);
1628 }
1629
1630 #ifdef CONFIG_COMPAT
1631 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1632 {
1633 struct rusage r;
1634
1635 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1636 who != RUSAGE_THREAD)
1637 return -EINVAL;
1638
1639 k_getrusage(current, who, &r);
1640 return put_compat_rusage(&r, ru);
1641 }
1642 #endif
1643
1644 SYSCALL_DEFINE1(umask, int, mask)
1645 {
1646 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1647 return mask;
1648 }
1649
1650 static int prctl_set_mm_exe_file_locked(struct mm_struct *mm, unsigned int fd)
1651 {
1652 struct fd exe;
1653 struct inode *inode;
1654 int err;
1655
1656 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
1657
1658 exe = fdget(fd);
1659 if (!exe.file)
1660 return -EBADF;
1661
1662 inode = file_inode(exe.file);
1663
1664 /*
1665 * Because the original mm->exe_file points to executable file, make
1666 * sure that this one is executable as well, to avoid breaking an
1667 * overall picture.
1668 */
1669 err = -EACCES;
1670 if (!S_ISREG(inode->i_mode) ||
1671 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1672 goto exit;
1673
1674 err = inode_permission(inode, MAY_EXEC);
1675 if (err)
1676 goto exit;
1677
1678 /*
1679 * Forbid mm->exe_file change if old file still mapped.
1680 */
1681 err = -EBUSY;
1682 if (mm->exe_file) {
1683 struct vm_area_struct *vma;
1684
1685 for (vma = mm->mmap; vma; vma = vma->vm_next)
1686 if (vma->vm_file &&
1687 path_equal(&vma->vm_file->f_path,
1688 &mm->exe_file->f_path))
1689 goto exit;
1690 }
1691
1692 /*
1693 * The symlink can be changed only once, just to disallow arbitrary
1694 * transitions malicious software might bring in. This means one
1695 * could make a snapshot over all processes running and monitor
1696 * /proc/pid/exe changes to notice unusual activity if needed.
1697 */
1698 err = -EPERM;
1699 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1700 goto exit;
1701
1702 err = 0;
1703 set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */
1704 exit:
1705 fdput(exe);
1706 return err;
1707 }
1708
1709 #ifdef CONFIG_CHECKPOINT_RESTORE
1710 /*
1711 * WARNING: we don't require any capability here so be very careful
1712 * in what is allowed for modification from userspace.
1713 */
1714 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1715 {
1716 unsigned long mmap_max_addr = TASK_SIZE;
1717 struct mm_struct *mm = current->mm;
1718 int error = -EINVAL, i;
1719
1720 static const unsigned char offsets[] = {
1721 offsetof(struct prctl_mm_map, start_code),
1722 offsetof(struct prctl_mm_map, end_code),
1723 offsetof(struct prctl_mm_map, start_data),
1724 offsetof(struct prctl_mm_map, end_data),
1725 offsetof(struct prctl_mm_map, start_brk),
1726 offsetof(struct prctl_mm_map, brk),
1727 offsetof(struct prctl_mm_map, start_stack),
1728 offsetof(struct prctl_mm_map, arg_start),
1729 offsetof(struct prctl_mm_map, arg_end),
1730 offsetof(struct prctl_mm_map, env_start),
1731 offsetof(struct prctl_mm_map, env_end),
1732 };
1733
1734 /*
1735 * Make sure the members are not somewhere outside
1736 * of allowed address space.
1737 */
1738 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1739 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1740
1741 if ((unsigned long)val >= mmap_max_addr ||
1742 (unsigned long)val < mmap_min_addr)
1743 goto out;
1744 }
1745
1746 /*
1747 * Make sure the pairs are ordered.
1748 */
1749 #define __prctl_check_order(__m1, __op, __m2) \
1750 ((unsigned long)prctl_map->__m1 __op \
1751 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1752 error = __prctl_check_order(start_code, <, end_code);
1753 error |= __prctl_check_order(start_data, <, end_data);
1754 error |= __prctl_check_order(start_brk, <=, brk);
1755 error |= __prctl_check_order(arg_start, <=, arg_end);
1756 error |= __prctl_check_order(env_start, <=, env_end);
1757 if (error)
1758 goto out;
1759 #undef __prctl_check_order
1760
1761 error = -EINVAL;
1762
1763 /*
1764 * @brk should be after @end_data in traditional maps.
1765 */
1766 if (prctl_map->start_brk <= prctl_map->end_data ||
1767 prctl_map->brk <= prctl_map->end_data)
1768 goto out;
1769
1770 /*
1771 * Neither we should allow to override limits if they set.
1772 */
1773 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1774 prctl_map->start_brk, prctl_map->end_data,
1775 prctl_map->start_data))
1776 goto out;
1777
1778 /*
1779 * Someone is trying to cheat the auxv vector.
1780 */
1781 if (prctl_map->auxv_size) {
1782 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1783 goto out;
1784 }
1785
1786 /*
1787 * Finally, make sure the caller has the rights to
1788 * change /proc/pid/exe link: only local root should
1789 * be allowed to.
1790 */
1791 if (prctl_map->exe_fd != (u32)-1) {
1792 struct user_namespace *ns = current_user_ns();
1793 const struct cred *cred = current_cred();
1794
1795 if (!uid_eq(cred->uid, make_kuid(ns, 0)) ||
1796 !gid_eq(cred->gid, make_kgid(ns, 0)))
1797 goto out;
1798 }
1799
1800 error = 0;
1801 out:
1802 return error;
1803 }
1804
1805 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1806 {
1807 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1808 unsigned long user_auxv[AT_VECTOR_SIZE];
1809 struct mm_struct *mm = current->mm;
1810 int error;
1811
1812 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1813 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1814
1815 if (opt == PR_SET_MM_MAP_SIZE)
1816 return put_user((unsigned int)sizeof(prctl_map),
1817 (unsigned int __user *)addr);
1818
1819 if (data_size != sizeof(prctl_map))
1820 return -EINVAL;
1821
1822 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1823 return -EFAULT;
1824
1825 error = validate_prctl_map(&prctl_map);
1826 if (error)
1827 return error;
1828
1829 if (prctl_map.auxv_size) {
1830 memset(user_auxv, 0, sizeof(user_auxv));
1831 if (copy_from_user(user_auxv,
1832 (const void __user *)prctl_map.auxv,
1833 prctl_map.auxv_size))
1834 return -EFAULT;
1835
1836 /* Last entry must be AT_NULL as specification requires */
1837 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1838 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1839 }
1840
1841 down_write(&mm->mmap_sem);
1842 if (prctl_map.exe_fd != (u32)-1)
1843 error = prctl_set_mm_exe_file_locked(mm, prctl_map.exe_fd);
1844 downgrade_write(&mm->mmap_sem);
1845 if (error)
1846 goto out;
1847
1848 /*
1849 * We don't validate if these members are pointing to
1850 * real present VMAs because application may have correspond
1851 * VMAs already unmapped and kernel uses these members for statistics
1852 * output in procfs mostly, except
1853 *
1854 * - @start_brk/@brk which are used in do_brk but kernel lookups
1855 * for VMAs when updating these memvers so anything wrong written
1856 * here cause kernel to swear at userspace program but won't lead
1857 * to any problem in kernel itself
1858 */
1859
1860 mm->start_code = prctl_map.start_code;
1861 mm->end_code = prctl_map.end_code;
1862 mm->start_data = prctl_map.start_data;
1863 mm->end_data = prctl_map.end_data;
1864 mm->start_brk = prctl_map.start_brk;
1865 mm->brk = prctl_map.brk;
1866 mm->start_stack = prctl_map.start_stack;
1867 mm->arg_start = prctl_map.arg_start;
1868 mm->arg_end = prctl_map.arg_end;
1869 mm->env_start = prctl_map.env_start;
1870 mm->env_end = prctl_map.env_end;
1871
1872 /*
1873 * Note this update of @saved_auxv is lockless thus
1874 * if someone reads this member in procfs while we're
1875 * updating -- it may get partly updated results. It's
1876 * known and acceptable trade off: we leave it as is to
1877 * not introduce additional locks here making the kernel
1878 * more complex.
1879 */
1880 if (prctl_map.auxv_size)
1881 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
1882
1883 error = 0;
1884 out:
1885 up_read(&mm->mmap_sem);
1886 return error;
1887 }
1888 #endif /* CONFIG_CHECKPOINT_RESTORE */
1889
1890 static int prctl_set_mm(int opt, unsigned long addr,
1891 unsigned long arg4, unsigned long arg5)
1892 {
1893 struct mm_struct *mm = current->mm;
1894 struct vm_area_struct *vma;
1895 int error;
1896
1897 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
1898 opt != PR_SET_MM_MAP &&
1899 opt != PR_SET_MM_MAP_SIZE)))
1900 return -EINVAL;
1901
1902 #ifdef CONFIG_CHECKPOINT_RESTORE
1903 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
1904 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
1905 #endif
1906
1907 if (!capable(CAP_SYS_RESOURCE))
1908 return -EPERM;
1909
1910 if (opt == PR_SET_MM_EXE_FILE) {
1911 down_write(&mm->mmap_sem);
1912 error = prctl_set_mm_exe_file_locked(mm, (unsigned int)addr);
1913 up_write(&mm->mmap_sem);
1914 return error;
1915 }
1916
1917 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1918 return -EINVAL;
1919
1920 error = -EINVAL;
1921
1922 down_read(&mm->mmap_sem);
1923 vma = find_vma(mm, addr);
1924
1925 switch (opt) {
1926 case PR_SET_MM_START_CODE:
1927 mm->start_code = addr;
1928 break;
1929 case PR_SET_MM_END_CODE:
1930 mm->end_code = addr;
1931 break;
1932 case PR_SET_MM_START_DATA:
1933 mm->start_data = addr;
1934 break;
1935 case PR_SET_MM_END_DATA:
1936 mm->end_data = addr;
1937 break;
1938
1939 case PR_SET_MM_START_BRK:
1940 if (addr <= mm->end_data)
1941 goto out;
1942
1943 if (check_data_rlimit(rlimit(RLIMIT_DATA), mm->brk, addr,
1944 mm->end_data, mm->start_data))
1945 goto out;
1946
1947 mm->start_brk = addr;
1948 break;
1949
1950 case PR_SET_MM_BRK:
1951 if (addr <= mm->end_data)
1952 goto out;
1953
1954 if (check_data_rlimit(rlimit(RLIMIT_DATA), addr, mm->start_brk,
1955 mm->end_data, mm->start_data))
1956 goto out;
1957
1958 mm->brk = addr;
1959 break;
1960
1961 /*
1962 * If command line arguments and environment
1963 * are placed somewhere else on stack, we can
1964 * set them up here, ARG_START/END to setup
1965 * command line argumets and ENV_START/END
1966 * for environment.
1967 */
1968 case PR_SET_MM_START_STACK:
1969 case PR_SET_MM_ARG_START:
1970 case PR_SET_MM_ARG_END:
1971 case PR_SET_MM_ENV_START:
1972 case PR_SET_MM_ENV_END:
1973 if (!vma) {
1974 error = -EFAULT;
1975 goto out;
1976 }
1977 if (opt == PR_SET_MM_START_STACK)
1978 mm->start_stack = addr;
1979 else if (opt == PR_SET_MM_ARG_START)
1980 mm->arg_start = addr;
1981 else if (opt == PR_SET_MM_ARG_END)
1982 mm->arg_end = addr;
1983 else if (opt == PR_SET_MM_ENV_START)
1984 mm->env_start = addr;
1985 else if (opt == PR_SET_MM_ENV_END)
1986 mm->env_end = addr;
1987 break;
1988
1989 /*
1990 * This doesn't move auxiliary vector itself
1991 * since it's pinned to mm_struct, but allow
1992 * to fill vector with new values. It's up
1993 * to a caller to provide sane values here
1994 * otherwise user space tools which use this
1995 * vector might be unhappy.
1996 */
1997 case PR_SET_MM_AUXV: {
1998 unsigned long user_auxv[AT_VECTOR_SIZE];
1999
2000 if (arg4 > sizeof(user_auxv))
2001 goto out;
2002 up_read(&mm->mmap_sem);
2003
2004 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
2005 return -EFAULT;
2006
2007 /* Make sure the last entry is always AT_NULL */
2008 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2009 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2010
2011 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2012
2013 task_lock(current);
2014 memcpy(mm->saved_auxv, user_auxv, arg4);
2015 task_unlock(current);
2016
2017 return 0;
2018 }
2019 default:
2020 goto out;
2021 }
2022
2023 error = 0;
2024 out:
2025 up_read(&mm->mmap_sem);
2026 return error;
2027 }
2028
2029 #ifdef CONFIG_CHECKPOINT_RESTORE
2030 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2031 {
2032 return put_user(me->clear_child_tid, tid_addr);
2033 }
2034 #else
2035 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2036 {
2037 return -EINVAL;
2038 }
2039 #endif
2040
2041 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2042 unsigned long, arg4, unsigned long, arg5)
2043 {
2044 struct task_struct *me = current;
2045 unsigned char comm[sizeof(me->comm)];
2046 long error;
2047
2048 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2049 if (error != -ENOSYS)
2050 return error;
2051
2052 error = 0;
2053 switch (option) {
2054 case PR_SET_PDEATHSIG:
2055 if (!valid_signal(arg2)) {
2056 error = -EINVAL;
2057 break;
2058 }
2059 me->pdeath_signal = arg2;
2060 break;
2061 case PR_GET_PDEATHSIG:
2062 error = put_user(me->pdeath_signal, (int __user *)arg2);
2063 break;
2064 case PR_GET_DUMPABLE:
2065 error = get_dumpable(me->mm);
2066 break;
2067 case PR_SET_DUMPABLE:
2068 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2069 error = -EINVAL;
2070 break;
2071 }
2072 set_dumpable(me->mm, arg2);
2073 break;
2074
2075 case PR_SET_UNALIGN:
2076 error = SET_UNALIGN_CTL(me, arg2);
2077 break;
2078 case PR_GET_UNALIGN:
2079 error = GET_UNALIGN_CTL(me, arg2);
2080 break;
2081 case PR_SET_FPEMU:
2082 error = SET_FPEMU_CTL(me, arg2);
2083 break;
2084 case PR_GET_FPEMU:
2085 error = GET_FPEMU_CTL(me, arg2);
2086 break;
2087 case PR_SET_FPEXC:
2088 error = SET_FPEXC_CTL(me, arg2);
2089 break;
2090 case PR_GET_FPEXC:
2091 error = GET_FPEXC_CTL(me, arg2);
2092 break;
2093 case PR_GET_TIMING:
2094 error = PR_TIMING_STATISTICAL;
2095 break;
2096 case PR_SET_TIMING:
2097 if (arg2 != PR_TIMING_STATISTICAL)
2098 error = -EINVAL;
2099 break;
2100 case PR_SET_NAME:
2101 comm[sizeof(me->comm) - 1] = 0;
2102 if (strncpy_from_user(comm, (char __user *)arg2,
2103 sizeof(me->comm) - 1) < 0)
2104 return -EFAULT;
2105 set_task_comm(me, comm);
2106 proc_comm_connector(me);
2107 break;
2108 case PR_GET_NAME:
2109 get_task_comm(comm, me);
2110 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2111 return -EFAULT;
2112 break;
2113 case PR_GET_ENDIAN:
2114 error = GET_ENDIAN(me, arg2);
2115 break;
2116 case PR_SET_ENDIAN:
2117 error = SET_ENDIAN(me, arg2);
2118 break;
2119 case PR_GET_SECCOMP:
2120 error = prctl_get_seccomp();
2121 break;
2122 case PR_SET_SECCOMP:
2123 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2124 break;
2125 case PR_GET_TSC:
2126 error = GET_TSC_CTL(arg2);
2127 break;
2128 case PR_SET_TSC:
2129 error = SET_TSC_CTL(arg2);
2130 break;
2131 case PR_TASK_PERF_EVENTS_DISABLE:
2132 error = perf_event_task_disable();
2133 break;
2134 case PR_TASK_PERF_EVENTS_ENABLE:
2135 error = perf_event_task_enable();
2136 break;
2137 case PR_GET_TIMERSLACK:
2138 error = current->timer_slack_ns;
2139 break;
2140 case PR_SET_TIMERSLACK:
2141 if (arg2 <= 0)
2142 current->timer_slack_ns =
2143 current->default_timer_slack_ns;
2144 else
2145 current->timer_slack_ns = arg2;
2146 break;
2147 case PR_MCE_KILL:
2148 if (arg4 | arg5)
2149 return -EINVAL;
2150 switch (arg2) {
2151 case PR_MCE_KILL_CLEAR:
2152 if (arg3 != 0)
2153 return -EINVAL;
2154 current->flags &= ~PF_MCE_PROCESS;
2155 break;
2156 case PR_MCE_KILL_SET:
2157 current->flags |= PF_MCE_PROCESS;
2158 if (arg3 == PR_MCE_KILL_EARLY)
2159 current->flags |= PF_MCE_EARLY;
2160 else if (arg3 == PR_MCE_KILL_LATE)
2161 current->flags &= ~PF_MCE_EARLY;
2162 else if (arg3 == PR_MCE_KILL_DEFAULT)
2163 current->flags &=
2164 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2165 else
2166 return -EINVAL;
2167 break;
2168 default:
2169 return -EINVAL;
2170 }
2171 break;
2172 case PR_MCE_KILL_GET:
2173 if (arg2 | arg3 | arg4 | arg5)
2174 return -EINVAL;
2175 if (current->flags & PF_MCE_PROCESS)
2176 error = (current->flags & PF_MCE_EARLY) ?
2177 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2178 else
2179 error = PR_MCE_KILL_DEFAULT;
2180 break;
2181 case PR_SET_MM:
2182 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2183 break;
2184 case PR_GET_TID_ADDRESS:
2185 error = prctl_get_tid_address(me, (int __user **)arg2);
2186 break;
2187 case PR_SET_CHILD_SUBREAPER:
2188 me->signal->is_child_subreaper = !!arg2;
2189 break;
2190 case PR_GET_CHILD_SUBREAPER:
2191 error = put_user(me->signal->is_child_subreaper,
2192 (int __user *)arg2);
2193 break;
2194 case PR_SET_NO_NEW_PRIVS:
2195 if (arg2 != 1 || arg3 || arg4 || arg5)
2196 return -EINVAL;
2197
2198 task_set_no_new_privs(current);
2199 break;
2200 case PR_GET_NO_NEW_PRIVS:
2201 if (arg2 || arg3 || arg4 || arg5)
2202 return -EINVAL;
2203 return task_no_new_privs(current) ? 1 : 0;
2204 case PR_GET_THP_DISABLE:
2205 if (arg2 || arg3 || arg4 || arg5)
2206 return -EINVAL;
2207 error = !!(me->mm->def_flags & VM_NOHUGEPAGE);
2208 break;
2209 case PR_SET_THP_DISABLE:
2210 if (arg3 || arg4 || arg5)
2211 return -EINVAL;
2212 down_write(&me->mm->mmap_sem);
2213 if (arg2)
2214 me->mm->def_flags |= VM_NOHUGEPAGE;
2215 else
2216 me->mm->def_flags &= ~VM_NOHUGEPAGE;
2217 up_write(&me->mm->mmap_sem);
2218 break;
2219 case PR_MPX_ENABLE_MANAGEMENT:
2220 if (arg2 || arg3 || arg4 || arg5)
2221 return -EINVAL;
2222 error = MPX_ENABLE_MANAGEMENT(me);
2223 break;
2224 case PR_MPX_DISABLE_MANAGEMENT:
2225 if (arg2 || arg3 || arg4 || arg5)
2226 return -EINVAL;
2227 error = MPX_DISABLE_MANAGEMENT(me);
2228 break;
2229 case PR_SET_FP_MODE:
2230 error = SET_FP_MODE(me, arg2);
2231 break;
2232 case PR_GET_FP_MODE:
2233 error = GET_FP_MODE(me);
2234 break;
2235 default:
2236 error = -EINVAL;
2237 break;
2238 }
2239 return error;
2240 }
2241
2242 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2243 struct getcpu_cache __user *, unused)
2244 {
2245 int err = 0;
2246 int cpu = raw_smp_processor_id();
2247
2248 if (cpup)
2249 err |= put_user(cpu, cpup);
2250 if (nodep)
2251 err |= put_user(cpu_to_node(cpu), nodep);
2252 return err ? -EFAULT : 0;
2253 }
2254
2255 /**
2256 * do_sysinfo - fill in sysinfo struct
2257 * @info: pointer to buffer to fill
2258 */
2259 static int do_sysinfo(struct sysinfo *info)
2260 {
2261 unsigned long mem_total, sav_total;
2262 unsigned int mem_unit, bitcount;
2263 struct timespec tp;
2264
2265 memset(info, 0, sizeof(struct sysinfo));
2266
2267 get_monotonic_boottime(&tp);
2268 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2269
2270 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2271
2272 info->procs = nr_threads;
2273
2274 si_meminfo(info);
2275 si_swapinfo(info);
2276
2277 /*
2278 * If the sum of all the available memory (i.e. ram + swap)
2279 * is less than can be stored in a 32 bit unsigned long then
2280 * we can be binary compatible with 2.2.x kernels. If not,
2281 * well, in that case 2.2.x was broken anyways...
2282 *
2283 * -Erik Andersen <andersee@debian.org>
2284 */
2285
2286 mem_total = info->totalram + info->totalswap;
2287 if (mem_total < info->totalram || mem_total < info->totalswap)
2288 goto out;
2289 bitcount = 0;
2290 mem_unit = info->mem_unit;
2291 while (mem_unit > 1) {
2292 bitcount++;
2293 mem_unit >>= 1;
2294 sav_total = mem_total;
2295 mem_total <<= 1;
2296 if (mem_total < sav_total)
2297 goto out;
2298 }
2299
2300 /*
2301 * If mem_total did not overflow, multiply all memory values by
2302 * info->mem_unit and set it to 1. This leaves things compatible
2303 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2304 * kernels...
2305 */
2306
2307 info->mem_unit = 1;
2308 info->totalram <<= bitcount;
2309 info->freeram <<= bitcount;
2310 info->sharedram <<= bitcount;
2311 info->bufferram <<= bitcount;
2312 info->totalswap <<= bitcount;
2313 info->freeswap <<= bitcount;
2314 info->totalhigh <<= bitcount;
2315 info->freehigh <<= bitcount;
2316
2317 out:
2318 return 0;
2319 }
2320
2321 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2322 {
2323 struct sysinfo val;
2324
2325 do_sysinfo(&val);
2326
2327 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2328 return -EFAULT;
2329
2330 return 0;
2331 }
2332
2333 #ifdef CONFIG_COMPAT
2334 struct compat_sysinfo {
2335 s32 uptime;
2336 u32 loads[3];
2337 u32 totalram;
2338 u32 freeram;
2339 u32 sharedram;
2340 u32 bufferram;
2341 u32 totalswap;
2342 u32 freeswap;
2343 u16 procs;
2344 u16 pad;
2345 u32 totalhigh;
2346 u32 freehigh;
2347 u32 mem_unit;
2348 char _f[20-2*sizeof(u32)-sizeof(int)];
2349 };
2350
2351 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2352 {
2353 struct sysinfo s;
2354
2355 do_sysinfo(&s);
2356
2357 /* Check to see if any memory value is too large for 32-bit and scale
2358 * down if needed
2359 */
2360 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2361 int bitcount = 0;
2362
2363 while (s.mem_unit < PAGE_SIZE) {
2364 s.mem_unit <<= 1;
2365 bitcount++;
2366 }
2367
2368 s.totalram >>= bitcount;
2369 s.freeram >>= bitcount;
2370 s.sharedram >>= bitcount;
2371 s.bufferram >>= bitcount;
2372 s.totalswap >>= bitcount;
2373 s.freeswap >>= bitcount;
2374 s.totalhigh >>= bitcount;
2375 s.freehigh >>= bitcount;
2376 }
2377
2378 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2379 __put_user(s.uptime, &info->uptime) ||
2380 __put_user(s.loads[0], &info->loads[0]) ||
2381 __put_user(s.loads[1], &info->loads[1]) ||
2382 __put_user(s.loads[2], &info->loads[2]) ||
2383 __put_user(s.totalram, &info->totalram) ||
2384 __put_user(s.freeram, &info->freeram) ||
2385 __put_user(s.sharedram, &info->sharedram) ||
2386 __put_user(s.bufferram, &info->bufferram) ||
2387 __put_user(s.totalswap, &info->totalswap) ||
2388 __put_user(s.freeswap, &info->freeswap) ||
2389 __put_user(s.procs, &info->procs) ||
2390 __put_user(s.totalhigh, &info->totalhigh) ||
2391 __put_user(s.freehigh, &info->freehigh) ||
2392 __put_user(s.mem_unit, &info->mem_unit))
2393 return -EFAULT;
2394
2395 return 0;
2396 }
2397 #endif /* CONFIG_COMPAT */
Linux with added FPC-III support